if(CMAKE_COMPILER_IS_GNUCXX)
    execute_process(COMMAND ${CMAKE_C_COMPILER} -dumpversion OUTPUT_VARIABLE GCC_VERSION)
    if (GCC_VERSION VERSION_GREATER 4.7 OR GCC_VERSION VERSION_EQUAL 4.7)
        message(STATUS "C++11 activated.")
        add_definitions("-std=gnu++11")
    elseif(GCC_VERSION VERSION_GREATER 4.3 OR GCC_VERSION VERSION_EQUAL 4.3)
        message(WARNING "C++0x activated. If you get any errors update to a compiler which fully supports C++11")
        add_definitions("-std=gnu++0x")
    else ()
        message(FATAL_ERROR "C++11 needed. Therefore a gcc compiler with a version higher than 4.3 is needed.")
    endif()
else(CMAKE_COMPILER_IS_GNUCXX)
    add_definitions("-std=c++0x")
endif(CMAKE_COMPILER_IS_GNUCXX)
